This invention relates to an apparatus for lining the inner wall of a vessel with bricks comprising a work platform movable inside the vessel along its vertical axis and capable of rotating about the latter, retractable props for stabilizing the platform relative to the wall of the vessel, a robot for handling and laying the bricks, and a supervision booth.
The present invention, although not being limited thereto in its utility, is particularly useful as an apparatus for laying a refractory lining on the inner wall of a metallurgical converter.
Various robotized apparatuses (see, for example, LU-A-86,144 corresponding to U.S. patent application Ser. No. 915,635 filed Oct. 6, 1986, now U.S. Pat. No. 4,708,562, assigned to the assignee hereof, all of the contents of which are incorporated herein by reference) have already been proposed for automatically carrying out brick laying work which has heretofore usually been performed manually. As is well known, manual laying of bricks is unsatisfactory because of the difficult and undesirable working conditions. In fact, it will be appreciated that this work not only demands considerable physical effort (the weight of the refractory bricks being on the order of 40 kg), but also that the working conditions are extremely unpleasant because of the dust, the nasty smell of the refractory bricks and the continuous draft through the open converter which functions as a suction chimney.
On the other hand, carrying out this bricklaying work by means of a robot makes it necessary to initially solve a certain number of new and difficult problems. For example, because converters do not all have the same diameters and because the diameter of each converter varies according to its height, two standard types of bricks of different conicities must be manufactured so that the desired curves (matching the curves of the vessel) are obtained by carefully alternating between the types of bricks selected.
For manual brick-lining, it is merely necessary for the two types of bricks to be available on the platform, since the worker can usually select the appropriate type of brick. On the other hand, for the purpose of robotization, it is absolutely essential to provide complicated measuring and programming systems in order to determine and select the appropriate type of brick automatically. Moreover, so that robotized brick-lining is practicable and viable, the automatic operation must be at least as fast as the manual operation, so that it is possible to keep to the critical time allowed for the shutdown of a converter.
To solve these problems and to satisfy the conditions present in the vessel, the above mentioned U.S. patent application Ser. No. 915,635 proposes mounting two brick pallets on the work platform and depalletizing them as required. To simplify robotization and increase the work rate, the laying and depalletizing functions are also separated by providing an automatic depalletizing mechanism on the platform which automatically selects the type of brick from the relevant pallet required by the bricklaying supervision system; and a handling robot which picks up the bricks depalletized in this way and which lays them in place.
However, depalletization on the platform itself takes up a large amount of space, and as a result, the surface of the platform has to be of an appropriately large size. On the other hand, the surface of the platform must be limited so that it is also possible to line the upper part of a converter, where the cross-section progressively decreases. It follows then that this robotization system is difficult to put into effect for converters of relatively small size, if overcrowding of the platform is to be avoided. Moreover, another disadvantage of depalletization on the platform is that the idle time required for changing the pallets has to be taken into account.
Although systems for depalletizing outside the converter, with hoists for individual bricks, as described in German Patent Specification No. 2,914,651 and German Patent Specification No. 2,605,970, are known, nevertheless these systems are intended for manual bricklining. In other words, a robotized apparatus with depalletization outside the converter has not heretofore been known.